1. Field of the Invention
This invention is related to an image processing method, more particular to a method for analyzing object motion in multi-frames.
2. Description of Related Art
There are many reasons to generate noises in an image, such as the signal amplifier, inducing waste heat, interaction between lens and photo sensor, interfering with one another during transmission process. Each photo sensor configured to different lenses may cause different effect. In nowadays image processing application, blending and analyzing of multi-frame is widely discussed and used, but how to accurately analyze the motion relations between different frames is the big problem. Taking the 3D noise reduction as an example, once a wrong analysis result of the motion between different frames is used, cross-talk may often occur in the blended image. There are plenty of methods of analyzing object motion in multi-frame, but the analyzing speed like. A comparatively simple and effective way is the method of sum of absolute difference (SAD).
However, in a seriously noisy environment, it is easy to obtain a wrong analyzing result if the method of SAD is merely relied on. In addition, the consideration of taking the resulting absolute difference and the smallest block as the optimum approximate location where the block exists is rather unsuitable. Since in a seriously noisy environment, the value of the absolute difference is not small in reality. For example, when the difference between the maximum SAD and the minimum SAD is quite small in searched region, it is easy to cause error if the coordinates of the smallest value is identified as the corresponding coordinates. Moreover, it can indeed reduce the effect of noise if the likelihood function is used as a fundamental to analyze the object motion. However, it needs a very large calculation resource. Especially for the products using the complementary metal-oxide-semiconductor sensor (CMOS sensor) at high frame rate, a much higher calculation speed and efficiency is necessary. Such tedious and time consuming algorithm is difficult to be realized in a product for image processing.